EPA: Greenhouse gases are harmful to humans

The Environmental Protection Agency took a major step Monday toward regulating greenhouses gases, concluding that climate changing pollution threatens the public health and the environment.

The EPA said that the scientific evidence surrounding climate change clearly shows that greenhouse gases "threaten the public health and welfare of the American people" and that the pollutants — mainly carbon dioxide from burning fossil fuels — should be regulated under the Clean Air Act.

Under a Supreme Court ruling, the finding of endangerment is needed before the EPA can regulate carbon dioxide and five other greenhouse gases released from power plants, factories and automobiles under the federal Clean Air Act.